stm32 Speex源码示例

以下是使用STM32CubeIDE和Speex库的示例代码：

#include "main.h"
#include "stm32f4xx_hal.h"
#include "speex/speex.h"

/* Speex */
#define FRAME_SIZE 160
#define ENCODED_FRAME_SIZE (FRAME_SIZE / 2 + 1)
#define BITRATE 16000

/* UART */
UART_HandleTypeDef huart2;

/* Speex variables */
SpeexBits bits;
void *enc_state;
void *dec_state;
int quality = 8;
int complexity = 3;
int vbr = 1;
int vad = 1;
int dtx = 0;
int denoise = 1;
int plc = 1;
int sample_rate = 16000;
int frames_per_packet = 1;
int packet_size = 0;
int16_t input_buffer[FRAME_SIZE];
uint8_t encoded_buffer[ENCODED_FRAME_SIZE];

/* Private function prototypes */
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);

int main(void)
{
  /* MCU Configuration */
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_USART2_UART_Init();

  /* Speex initialization */
  speex_bits_init(&bits);
  enc_state = speex_encoder_init(&speex_nb_mode);
  speex_encoder_ctl(enc_state, SPEEX_SET_QUALITY, &quality);
  speex_encoder_ctl(enc_state, SPEEX_SET_COMPLEXITY, &complexity);
  speex_encoder_ctl(enc_state, SPEEX_SET_VBR, &vbr);
  speex_encoder_ctl(enc_state, SPEEX_SET_VAD, &vad);
  speex_encoder_ctl(enc_state, SPEEX_SET_DTX, &dtx);
  speex_encoder_ctl(enc_state, SPEEX_SET_SAMPLING_RATE, &sample_rate);
  speex_encoder_ctl(enc_state, SPEEX_SET_PLC_TUNING, &plc);
  speex_decoder_ctl(dec_state, SPEEX_SET_SAMPLING_RATE, &sample_rate);
  dec_state = speex_decoder_init(&speex_nb_mode);

  while (1)
  {
    /* Read audio data from ADC or microphone into input_buffer */
    /* ... */

    /* Encode audio data */
    speex_bits_reset(&bits);
    speex_encode_int(enc_state, input_buffer, &bits);
    packet_size = speex_bits_write(&bits, (char *)encoded_buffer, ENCODED_FRAME_SIZE);

    /* Transmit encoded audio data over UART */
    HAL_UART_Transmit(&huart2, encoded_buffer, packet_size, HAL_MAX_DELAY);

    /* Decode received audio data */
    if (HAL_UART_Receive(&huart2, encoded_buffer, packet_size, HAL_MAX_DELAY) == HAL_OK)
    {
      speex_bits_reset(&bits);
      speex_bits_read_from(&bits, (char *)encoded_buffer, packet_size);
      speex_decode_int(dec_state, &bits, input_buffer);
    }
  }
}

/* System Clock Configuration */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 8;
  RCC_OscInitStruct.PLL.PLLN = 50;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 2;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
                              | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3) != HAL_OK)
  {
    Error_Handler();
  }
}

/* USART2 Initialization Function */
static void MX_USART2_UART_Init(void)
{
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
}

/* GPIO Initialization Function */
static void MX_GPIO_Init(void)
{
  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();
}

/* Error handler */
void Error_Handler(void)
{
  while (1)
  {
  }
}

在这个示例代码中，我们使用Speex库对音频数据进行编码和解码。首先，我们初始化Speex库并设置编码器和解码器的参数。然后，我们在一个无限循环中读取音频数据，对其进行编码，并通过UART传输编码后的数据。接收到的数据也通过UART传输，并解码成原始音频数据。